Voice over IP (“VoIP”) is a relatively recent development that is utilized to transmit voice conversations over a data network using the Internet Protocol (“IP”). Such a data network may be the Internet or a corporate intranet, or any IP network. There are several potential benefits for moving voice over a data network using IP. First, there is a savings in money compared to the need to use traditional tolled telecommunications networks. Additionally, Voice over IP enables the management of voice and data over a single network. And, with the use of IP phones, moves, adds and changes are easier and less expensive to implement. Moreover, additional and integrated new services, including integrated messaging, bandwidth on demand, voice e-mails, the development of “voice portals” on the Web, simplified setting up and tearing down, and transferring of phone calls are capable.
One of the advantages of Voice over IP is the ability to easily and inexpensively connect remote systems together. The concept of connecting multiple field office phone systems together is not new. Indeed, this is the primary purpose of the tie trunk. While the tie trunk approach eliminates the long distance phone charges between facilities, it is somewhat offset by the dedicated cost of the tie lines themselves. Tie-lines are dedicated to the task of connecting callers between phone systems and must be engineered to provide a worst-case traffic scenario. Even if there is a single call in progress, the other tie trunks sit idle and cannot be used for other purposes.
In addition to the high cost and inefficiencies of tie-lines, there is another major drawback: each phone system in the network is an independent entity, which does not share information. Even though the phone system may be a modern, sophisticated device with the ability to display the status of its local telephone sets, the user must dial the access code to the remote site, enter the desired extension number and listen for either a ring or a busy signal to determine the status of the called party.
Using Voice over IP technology, phone systems can communicate with each other over existing IP data networks typically present between remote offices. This feature alone can eliminate the need for expensive, dedicated circuits between facilities. The shared bandwidth can also be used for voice calls and data communication simultaneously; no bandwidth is dedicated to one or the other.